Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 18 de 18
Filtrar
Más filtros










Base de datos
Intervalo de año de publicación
1.
Artículo en Inglés | MEDLINE | ID: mdl-36981625

RESUMEN

Highly developed cognitive abilities are an important prerequisite for reaching elite athletic levels. This study aimed to investigate the effect of an acute sprint interval training (SIT) session on the cognitive performance of amateur and elite players. Eighteen amateur and ten elite male basketball players were included in this study. They were asked to perform an acute SIT consisting of the Wingate Test (i.e., four bouts of 30 s all-out sprints) on a cycle ergometer, interspersed with 4 min of active recovery. Before and after the acute SIT, three cognitive tests (i.e., Change Detection Test, Timewall Test, Mackworth Clock Test) were performed. Exercise-induced changes in cognitive performance and between-group differences were analyzed. We did not observe significant between-group differences in the performance of any cognitive test at the pretest, but elite basketball players outperformed the amateur players in specific measures of the Change Detection Test and Timewall Test after the acute SIT (p < 0.05). In addition, for the Clock Test, only the elite basketball players' performance improved from pre- to posttest. The current study's findings suggest that male elite basketball players, compared to amateur basketball players, can preserve their cognitive performance after an acute bout of SIT.


Asunto(s)
Rendimiento Atlético , Baloncesto , Entrenamiento de Intervalos de Alta Intensidad , Masculino , Humanos , Atletas , Cognición
2.
J Sport Rehabil ; 31(4): 428-441, 2022 05 01.
Artículo en Inglés | MEDLINE | ID: mdl-35104787

RESUMEN

CONTEXT: Athletic skills such as balance are considered physical skills. However, these skills may not just improve by physical training, but also by mental training. The purpose of this study was to investigate the effects of mental training programs on balance skills and hemodynamic responses of the prefrontal cortex. DESIGN: Randomized controlled trial. METHODS: Fifty-seven healthy adults (28 females, 29 males), aged between 18-25 years, participated in this study. Participants were randomly assigned to 3 groups: virtual reality mental training (VRMT) group, conventional mental training (CMT) group, and control group. The training program included action observation and motor imagery practices with balance exercise videos. The VRMT group trained with a VR head-mounted display, while the CMT group trained with a non-immersive computer screen, for 30 minutes, 3 days per week for 4 weeks. At baseline and after 4 weeks of training, balance was investigated with stabilometry and Star Excursion Balance Test (SEBT). Balance tests were performed with simultaneous functional near-infrared spectroscopy (fNIRS) imaging to measure prefrontal cortex oxygenation. RESULTS: For the stabilometry test, at least 1 variable improved significantly in both VRMT and CMT groups but not in the control group. For SEBT, composite reach distance significantly increased in both VRMT and CMT groups but significantly decreased in the control group. For separate directional scores, reach distance was significantly increased in both mental training groups for nondominant leg posterolateral and posteromedial directions, and dominant leg posterolateral direction, while nondominant posteromedial score was significantly increased only in the VRMT group. Between-group comparisons showed that dominant leg posteromedial and posterolateral score improvements were significantly higher than control group for both mental training groups, while nondominant leg improvements were significantly higher than control group only for the VRMT group. The fNIRS oxyhemoglobin levels were not significantly changed during stabilometry tests. However, oxyhemoglobin levels significantly reduced only in the control group during SEBT. CONCLUSIONS: Our findings suggest that both mental training interventions can significantly improve balance test results. Additionally, VRMT may have some advantages over CMT. These findings are promising for the use of mental training in prevention and rehabilitation for special populations such as athletes and older adults.


Asunto(s)
Equilibrio Postural , Realidad Virtual , Adolescente , Adulto , Terapia por Ejercicio , Femenino , Humanos , Masculino , Oxihemoglobinas , Equilibrio Postural/fisiología , Espectroscopía Infrarroja Corta , Adulto Joven
3.
J Clin Rheumatol ; 28(2): e330-e333, 2022 03 01.
Artículo en Inglés | MEDLINE | ID: mdl-34665572

RESUMEN

BACKGROUND/OBJECTIVE: Anaerobic exercise capacity is an important component of performing daily activities during childhood. However, diminished anaerobic exercise capacity has been reported in children with chronic conditions. Therefore, the aim of this study was to compare anaerobic exercise capacities between children with familial Mediterranean fever (FMF) and healthy peers. METHODS: Twenty-one children with FMF (FMF group) and 21 physically matched healthy controls (control group) were included. Peak power, peak power/kg, average power, and average power were evaluated using the Wingate Anaerobic Test. RESULTS: The peak power (FMF group: 254.8 W [IQR 25/75: 216.4/293.0 W] vs control group: 333.7 W [IQR 25/75: 241.3/570.5 W], p = 0.009), peak power/kg (FMF group: 6.3 W/kg [IQR 25/75: 5.2/7.0 W/kg] vs control group: 7.0 W/kg [IQR 25/75: 6.1/8.6 W/kg], p = 0.046), average power (FMF group: 186.0 W [IQR 25/75: 164.3/211.2 W] vs control group: 231.8 W [IQR 25/75: 181.8/338.1 W], p = 0.006), and average power/kg (FMF group: 4.5 W/kg [IQR 25/75: 3.8/5.0 W/kg] vs control group: 5.1 W/kg [IQR 25/75: 4.2/5.9 W/kg], p = 0.040) were found significantly higher in the control group compared with FMF group. CONCLUSIONS: Children with FMF seems to have diminished anaerobic exercise capacity compared with their healthy peers.


Asunto(s)
Fiebre Mediterránea Familiar , Anaerobiosis , Niño , Tolerancia al Ejercicio , Fiebre Mediterránea Familiar/diagnóstico , Estado de Salud , Humanos
4.
Gen Physiol Biophys ; 40(5): 387-396, 2021 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-34602452

RESUMEN

This study compared the hemodynamic changes in the prefrontal cortex during sprint interval training (SIT) and recovery periods in sedentary and athletes. SIT was performed on a cycling ergometer on 12 male athletes and 9 sedentary participants. A functional near-infrared spectroscopy (fNIRS) device was used to record the hemodynamic changes of the prefrontal cortex throughout the protocol. The oxyhemoglobin (Oxy-Hb) levels in the prefrontal cortex were increased significantly, and the power outputs were decreased in repetitive Wingate anaerobic tests (WAnTs) in Sedentary and Athletes group (p < 0.001). In addition, the Sedentary group had higher Oxy-Hb values (p < 0.001). However, the recovery times decreased significantly after all WAnTs (p < 0.05). Despite the increased fatigue, athletes performed better with less Oxy-Hb than the sedentary participants. Also, the recovery of the Oxy-Hb values in the prefrontal region was faster in athletes. These results may highlight a possible brain adaptation in athletes.


Asunto(s)
Aclimatación , Encéfalo , Atletas , Hemodinámica , Humanos , Masculino
5.
Int J Occup Med Environ Health ; 31(2): 243-249, 2018 01 07.
Artículo en Inglés | MEDLINE | ID: mdl-29035401

RESUMEN

The skydiving/parachuting sport which has recently gained popularity is also known for its accidents and injuries. However, there are a few studies related to its occupational ergonomic risks and occupational musculoskeletal diseases. It has been reported that the sudden hyperextension of the neck during the parachute opening, so called opening shock results in neck pain. It has been found that the jumpers are subjected to an average deceleration of 3-5 times the earth's gravitational acceleration (3-5 G) during parachute opening shock. It is considered that the spinal cord is destabilized by the impact of this force. This study presents the occupational cervical disc herniation occurring in the case of a subject who has been working as a skydiving/parachuting instructor for 25 years, and the ergonomic risks specific to the sports of skydiving. There is a requirement for systematic and representative studies related to the administrative measures to be taken in order to prevent the occupational diseases that may occur in the case of skydivers, the personal protective equipment to be used, and the employee. Int J Occup Med Environ Health 2018;31(2):243-249.


Asunto(s)
Aviación , Desaceleración/efectos adversos , Degeneración del Disco Intervertebral/etiología , Desplazamiento del Disco Intervertebral/etiología , Enfermedades Profesionales/etiología , Traumatismos en Atletas , Dispositivos de Protección de la Cabeza/estadística & datos numéricos , Humanos , Degeneración del Disco Intervertebral/diagnóstico por imagen , Desplazamiento del Disco Intervertebral/diagnóstico por imagen , Imagen por Resonancia Magnética , Masculino , Persona de Mediana Edad , Dolor de Cuello/etiología , Enfermedades Profesionales/diagnóstico por imagen , Acúfeno
6.
Front Hum Neurosci ; 10: 174, 2016.
Artículo en Inglés | MEDLINE | ID: mdl-27148022

RESUMEN

Single bout of exercise can improve the performance on cognitive tasks. However, cognitive responses may be controversial due to different type, intensity, and duration of exercise. In addition, the mechanism of the effect of acute exercise on brain is still unclear. This study was aimed to investigate the effects of supramaximal exercise on cognitive tasks by means of brain oxygenation monitoring. The brain oxygenation of Prefrontal cortex (PFC) was measured on 35 healthy male volunteers via functional near infrared spectroscopy (fNIRS) system. Subjects performed 2-Back test before and after the supramaximal exercise wingate anerobic test (WAnT) lasting 30-s on cycle ergometer. The PFC oxygenation change evaluation revealed that PFC oxygenation rise during post-exercise 2-Back task was considerably higher than those in pre-exercise 2-Back task. In order to describe the relationship between oxygenation change and exercise performance, subjects were divided into two groups as high performers (HP) and low performers (LP) according to their peak power values (PP) obtained from the supramaximal test. The oxy-hemoglobin (oxy-Hb) values were compared between pre- and post-exercise conditions within subjects and also between subjects according to peak power. When performers were compared, in the HP group, the oxy-Hb values in post-exercise 2-Back test were significantly higher than those in pre-exercise 2-Back test. HP had significantly higher post-exercise oxy-Hb change (Δ) than those of LP. In addition, PP of the total group were significantly correlated with Δoxy-Hb.The key findings of the present study revealed that acute supramaximal exercise has an impact on the brain oxygenation during a cognitive task. Also, the higher the anerobic PP describes the larger the oxy-Hb response in post-exercise cognitive task. The current study also demonstrated a significant correlation between peak power (exercise load) and post-exercise hemodynamic responses (oxy-, deoxy- and total-Hb). The magnitude of this impact might be related with the physical performance capacities of the individuals. This can become a valuable parameter for future studies on human factor.

7.
J Diabetes Complications ; 26(4): 348-51, 2012.
Artículo en Inglés | MEDLINE | ID: mdl-22609217

RESUMEN

UNLABELLED: Physical activity is a substantial method in the management of children and adolescents with Type 1 diabetes mellitus but it is not considered as a treatment for diabetes. The aim of this study was to investigate the effects of Pilates exercises on metabolic control and physical performance in patients with type 1 diabetes mellitus. Thirty one sedentary patients with type 1 diabetes mellitus, ranging in age from 12 to 17 (experimental group, n=17 and control group, n=14) were submitted to 12 weeks of Pilates training. Participants underwent tests to determine the physical performance and metabolic control before and after 12 weeks of Pilates session. At the end of study, there were significant alterations in physical performance of the study group. Peak power, mean power, vertical jump and flexibility of study group increased. There were no alterations for this parameters in the control group. There was no significant difference for glycated hemoglobin (HbA1c) in both groups. CONCLUSIONS: Physical performance increased via Pilates exercises in the patients with type 1 DM. However there were no changes in metabolic control. In the present study, the positive effects of exercise on metabolic control could not be shown in patients with Type 1 DM.


Asunto(s)
Diabetes Mellitus Tipo 1/metabolismo , Técnicas de Ejercicio con Movimientos , Resistencia Física/fisiología , Adolescente , Niño , Terapia por Ejercicio , Femenino , Hemoglobina Glucada/metabolismo , Humanos , Masculino , Resultado del Tratamiento
8.
Clin Appl Thromb Hemost ; 17(4): 414-20, 2011 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-21078613

RESUMEN

Depending on type, duration, and intensity of the exercise, changes occur in hemostasis. In this study, we evaluated the changes in the parameters of coagulation and fibrinolytic systems that happened after the submaximal aerobic exercises by bicycle ergomater. Twelve healthy male participants whose ages were between 21 and 28 have been included. The venous samples have been drawn before the exercise as well as at the 0 th, 15th, and 60th minutes after the submaximal exercise. The values of prothrombin time (PT), active partial thromboplastin time (aPTT), D-dimer, fibrinogen, plasminogen activator inhibitor 1 (PAI-1) and thrombin-activatable fibrinolysis inhibitor (TAFI) have been measured. Plasminogen activator inhibitor 1 values have shown an insignificant increase after exercise (P = .328), whereas, it has decreased significantly during the resting period (P = .033) Postexercise 15th and 60th minutes TAFI values have decreased significantly comparing to basal and postexercise (0 th minute) values (P = .001). Fibrinolytic system activation is observed after acute submaximal aerobic exercise of sedentary healthy participants.


Asunto(s)
Carboxipeptidasa B2/sangre , Ejercicio Físico/fisiología , Conducta Sedentaria , Adulto , Coagulación Sanguínea/fisiología , Carboxipeptidasa B2/metabolismo , Productos de Degradación de Fibrina-Fibrinógeno/metabolismo , Fibrinógeno/metabolismo , Humanos , Masculino , Inhibidor 1 de Activador Plasminogénico/metabolismo , Adulto Joven
9.
Ann Nutr Metab ; 51(1): 53-8, 2007.
Artículo en Inglés | MEDLINE | ID: mdl-17356255

RESUMEN

BACKGROUND AND AIMS: Elevated plasma homocysteine (PH) levels have been identified as a risk factor for cardiovascular diseases. The aims of this study were to investigate the influences of submaximal acute aerobic exercise and aerobic training on PH levels and lipid profiles. METHODS: 69 volunteer subjects (21.12 +/- 2.08 years) were randomized to three groups as acute, training and control groups. Examination and blood samples were collected before and immediately after exercise in the acute group and before and 6 weeks later in the training and control groups. RESULTS: A significant increase in PH concentration was recorded immediately after aerobic exercise, compared with baseline values (p = 0.001). Although, in the training group, total cholesterol (p = 0.00) and LDL cholesterol (p = 0.001) decreased significantly after training, no significant changes in PH concentration, HDL cholesterol (p = 0.087) and triglyceride (p = 194) levels were found. CONCLUSIONS: It can be said that the PH level increases following submaximal acute aerobic exercise, but does not alter after submaximal aerobic training due to training duration or intensity. Therefore, submaximal aerobic training decreases lipid profiles independent of the PH level.


Asunto(s)
Ejercicio Físico/fisiología , Homocisteína/sangre , Lípidos/sangre , Adulto , Femenino , Humanos , Masculino , Factores de Tiempo
10.
Tohoku J Exp Med ; 208(2): 133-40, 2006 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-16434836

RESUMEN

Extremely low-frequency (0-300 Hz) electromagnetic fields (EMFs) generated by power lines, wiring and home appliances are ubiquitous in our environment. All populations are now exposed to EMF, and exposure to EMF may pose health risks. Some of the adverse health effects of EMF exposure are lipid peroxidation and cell damage in various tissues. This study has investigated the effects of EMF exposure and zinc administration on lipid peroxidation in the rat brain. Twenty-four male Sprague-Dawley rats were randomly allocated to three groups; they were maintained untreated for 6 months (control, n = 8), exposed to low-frequency (50 Hz) EMF for 5 minutes every other day for 6 months (n = 8), or exposed to EMF and received zinc sulfate daily (3 mg/kg/day) intraperitoneally (n = 8). We measured plasma levels of zinc and thiobarbituric acid reactive substances (TBARS), and levels of reduced glutathione (GSH) in erythrocytes. TBARS and GSH levels were also determined in the brain tissues. TBARS levels in the plasma and brain tissues were higher in EMF-exposed rats with or without zinc supplementation, than those in controls (p < 0.001). In addition, TBARS levels were significantly lower in the zinc-supplemented rats than those in the EMF-exposed rats (p < 0.001). GSH levels were significantly decreased in the brain and erythrocytes of the EMF-exposed rats (p < 0.01), and were highest in the zinc-supplemented rats (p < 0.001). Plasma zinc was significantly lower in the EMF-exposed rats than those in controls (p < 0.001), while it was highest in the zinc-supplemented rats (p < 0.001). The present study suggests that long-term exposure to low-frequency EMF increases lipid peroxidation in the brain, which may be ameliorated by zinc supplementation.


Asunto(s)
Encéfalo/metabolismo , Campos Electromagnéticos/efectos adversos , Peroxidación de Lípido/efectos de la radiación , Zinc/farmacología , Animales , Eritrocitos/metabolismo , Glutatión/sangre , Glutatión/metabolismo , Masculino , Estrés Oxidativo , Ratas , Ratas Sprague-Dawley , Sustancias Reactivas al Ácido Tiobarbitúrico/metabolismo , Zinc/sangre , Zinc/metabolismo
11.
Neuro Endocrinol Lett ; 26(5): 555-60, 2005 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-16264401

RESUMEN

OBJECTIVES: It is known that maternal deprivation (MD) may alter cognitive functions such as learning and memory in adult life by effecting normal growth and development. However, the mechanisms of these cognitive alterations are unknown. The aim of this study is to investigate the effects of maternal deprivation on cognition and melatonin production in adolescent male and female rats. METHODS: The litters were separated daily from their mothers for 6 hours on postnatal days 2 to 20. The spatial memory performance was evaluated using a Morris water maze between the postnatal 26th and 32nd days. Plasma melatonin levels were determined on postnatal days 42. RESULTS: MD-rats had longer escape latencies at the second, third and fifth days of training days and spend significantly less time in probe trial, compared to control animals. MAIN FINDINGS: The repeated maternal deprivation caused low blood melatonin levels and there was a significant negative correlation between blood melatonin levels and spatial memory performance in both of male and female adolescent rats. CONCLUSION: These results suggest an association between melatonin production and neurodevelopment. Further studies are needed to determine the interaction between maternal deprivation and pineal gland maturation/function.


Asunto(s)
Cognición/fisiología , Privación Materna , Melatonina/biosíntesis , Animales , Femenino , Masculino , Aprendizaje por Laberinto/fisiología , Melatonina/sangre , Memoria/fisiología , Desempeño Psicomotor/fisiología , Ratas , Ratas Wistar
12.
Int J Vitam Nutr Res ; 75(4): 243-50, 2005 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-16229340

RESUMEN

This study aimed to determine whether high-dose antioxidant supplementation had an impact on the acute exercise effects related to erythrocyte membrane mechanics. Experimental animals (n=32) were divided into four groups as control, exercised, supplemented, and supplemented + exercise. Four-week antioxidant supplementation (vitamin C, vitamin E, and zinc) was applied to experimental animals. Following acute exercise on a motor-driven rodent treadmill, erythrocyte aggregation and deformability, erythrocyte adhesion to endothelial cells, superoxide dismutase (SOD), and glutathione peroxidase activities of the erythrocytes were analyzed. In both supplemented and non-supplemented exercised groups, there was a significant decrease in SOD activities and erythrocyte aggregation, and an increase in adhesion to endothelial cell although there was no change on erythrocyte deformability. There were no differences in the responses to the exercise of supplemented and nonsupplemented rats. The data suggested that high-dose antioxidant supplementation did not alter the effects of acute exercise on erythrocyte membrane mechanics.


Asunto(s)
Antioxidantes/administración & dosificación , Suplementos Dietéticos , Endotelio Vascular/enzimología , Membrana Eritrocítica/metabolismo , Condicionamiento Físico Animal , Animales , Adhesión Celular/efectos de los fármacos , Células Cultivadas , Técnicas de Cocultivo , Endotelio Vascular/citología , Agregación Eritrocitaria/efectos de los fármacos , Masculino , Ratas , Ratas Wistar , Superóxido Dismutasa/metabolismo
13.
Biol Trace Elem Res ; 104(1): 47-56, 2005 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-15851832

RESUMEN

The effects of zinc and/or melatonin deficiencies on cellular immunity were investigated in rats infected with Toxoplasma gondii. A total of 50 adult male Sprague-Dawley rats were divided into 5 groups of 10 rats each. In group I, the rats were infected with T. gondii and fed a zinc-deficient diet; in group II, the rats were infected and their pineal gland was surgically removed. Group III included rats that were infected, pinealectomized, and fed a zinc-deficient diet. Group IV consisted of T. gondii-infested rats that received no treatment of any kind, and group V were normal controls. After 3 wk of treatment, all rats were sacrificed and the percentages of CD3, CD4, and CD8 lymphocytes, zinc, and melatonin levels in plasma and the percentage of lymphocyte in blood smears were analyzed. The CD3 ratios of groups I-III were significantly lower than those of groups IV and V (p<0.01). The CD4 lymphocytes were significantly higher in group IV than that in all other groups (p<0.05). In group IV, the CD8 lymphocytes were higher than in groups I-III (p<0.01) and those in group V were higher than for groups I and III (p<0.01). Lymphocyte incidence in group IV was higher than in the other four groups (p<0.01). The plasma zinc and plasma melatonin levels in groups I-III were significantly lower than those in the controls (p<0.01, both cases). These results suggest that zinc and/or melatonin deficiency have a negative influence on cellular immunity in rats with toxoplasmosis.


Asunto(s)
Inmunidad Celular/fisiología , Glándula Pineal/fisiología , Toxoplasmosis/inmunología , Zinc/deficiencia , Animales , Peso Corporal/fisiología , Recuento de Linfocitos , Melatonina/sangre , Melatonina/fisiología , Ratas , Ratas Sprague-Dawley , Espectrofotometría Atómica , Linfocitos T/inmunología
14.
Swiss Med Wkly ; 134(23-24): 359-63, 2004 Jun 12.
Artículo en Inglés | MEDLINE | ID: mdl-15318286

RESUMEN

PRINCIPLES: This study aims at investigating how zinc deficiency and pinealectomy affect nitric oxide levels in rats infected by Toxoplasma gondii. METHODS: The study was conducted on a total of 50 adult, male rats of Spraque-Dawley species. The study groups were as follows: General, intact control group (Group I, n = 10), infected control group (Group II, n = 10), infected and zinc-deficient group (Group III, n = 10), infected and pinealectomized group (Group IV, n = 10), infected, zinc-deficient and pinealectomized group (Group V, n = 10). After the experiment the rats were decapitated and levels of zinc, melatonin and total nitrite were identified in the blood samples collected. RESULTS: The total nitrite levels in groups IV and V were more than those in all other groups (p <0.01). The total nitrite levels in Group II were also higher than those in Groups I and III (p <0.01). Plasma zinc levels in the zinc-deficient group and zinc-deficient and pinealectomized group were lower than those in all other groups, while melatonin levels were lower in infected pinealectomized group (Group IV) and infected, zinc-deficient and pinealectomized group (Group V) than all others (p <0.01). CONCLUSIONS: The present study shows that plasma nitric oxide levels increase during Toxoplasma gondii infection, but this increase becomes more apparent in the presence of melatonin deficiency and is inhibited by zinc deficiency.


Asunto(s)
Melatonina/deficiencia , Óxido Nítrico/sangre , Toxoplasmosis/sangre , Toxoplasmosis/complicaciones , Zinc/deficiencia , Animales , Enfermedades Carenciales/sangre , Enfermedades Carenciales/parasitología , Masculino , Ratas , Ratas Sprague-Dawley , Estadísticas no Paramétricas
15.
Toxicology ; 195(1): 69-75, 2004 Jan 15.
Artículo en Inglés | MEDLINE | ID: mdl-14698569

RESUMEN

The present study was conducted to investigate how thyroid function in rats is affected by administration of 3 mg per kg per day of zinc and/or melatonin. The study was conducted with 40 Sprague-Dawley adult male rats equally divided into four groups: 1 (controls), 2 (zinc-only), 3 (melatonin-only) and 4 (zinc- and melatonin-supplemented). The supplementation was continued for 4 weeks after which the animals were sacrificed and plasma samples were obtained for determination of zinc, melatonin, free- and total triiodothyronine (T3), thyroxine (T4) and thyroid-stimulating hormone (TSH) levels. The free T3, T4 and TSH levels were lower in the melatonin group than in all other groups (P<0.01), while free- and total T3 levels were higher in the zinc group (P<0.01). The group that received zinc and melatonin combined had free thyroid hormone levels higher than the only melatonin group. These results show that melatonin has a thyroid function suppressing action, just the opposite to the actions of zinc. When zinc is administered along with melatonin, its thyroid function suppression is diminished.


Asunto(s)
Melatonina/antagonistas & inhibidores , Hormonas Tiroideas/metabolismo , Zinc/antagonistas & inhibidores , Animales , Inyecciones Intraperitoneales , Masculino , Melatonina/administración & dosificación , Melatonina/sangre , Ratas , Ratas Sprague-Dawley , Hormonas Tiroideas/sangre , Zinc/administración & dosificación , Zinc/sangre
16.
Endocr Res ; 29(4): 473-81, 2003 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-14682476

RESUMEN

The present study was conducted to investigate how pinealectomy and zinc deficiency separately or in combination affected thyroid hormones in rats. The study was carried out on 40 Sprague-Dawley male rats. The rats were equally allocated to four groups: Group 1 (control group), Group 2 (zinc-deficient group), Group 3 (pinealectomized group) and Group 4 (pinealectomized and zinc-deficient group). At the end of a 4-week study period, the rats were decapitated and blood samples were taken. The samples were examined in terms of plasma zinc, melatonin, free and total T3, T4, and TSH. It was found that free T3 and T4 levels in the pinealectomized group (Group 3) were higher than all others (p < 0.01) while free T3, T4, and TSH levels in the zinc-deficient group (Group 2) were lower than all others (p < 0.01). Free T3 and T4 levels in the pinealectomized zinc-deficient group (Group 4) were lower than those in Groups 1 and 3 and higher than those in Group 2 (p < 0.01). The findings obtained at the end of the study period show that pinealectomy has a stimulating and zinc deficiency has a suppressing effect on thyroid hormones and that the suppressing effect caused by zinc deficiency is partially balanced by pinealectomy.


Asunto(s)
Glándula Pineal/fisiología , Glándula Pineal/cirugía , Hormonas Tiroideas/sangre , Zinc/deficiencia , Animales , Masculino , Melatonina/sangre , Ratas , Ratas Sprague-Dawley , Tirotropina/sangre , Zinc/sangre
17.
Biol Trace Elem Res ; 96(1-3): 237-45, 2003.
Artículo en Inglés | MEDLINE | ID: mdl-14716103

RESUMEN

The effects of zinc (Zn) and/or melatonin supplementation on cellular immunity were investigated in rats infested with Toxoplasma gondii. Fifty Sprague-Dawley male rats were used for this study. All animals were fed a normal diet, ad libitum, containing 97 mg Zn/kg. They were divided into five experimental groups, as follows. Group I (n = 10) received intraperitoneal injections of zinc sulfate at a dose of 3 mg/kg/d for 3 wk. Group II (n = 10) received intraperitoneal injections of melatonin at a dose of 3 mg/kg/d for 3 wk. Group III (n = 10) received intraperitoneal injections of zinc sulfate (3 mg/kg/d) and melatonin (3 mg/kg/d) for 3 wk. Group IV (n = 10) was infested controls. Group V (n = 10) was healthy controls. There were no differences in the percentage of CD3+ lymphocytes among all groups. For groups I-III, the CD4+ and CD8+ ratios were higher than those of the groups IV and V controls (p<0.01). Similarly, the total lymphocyte ratios in groups I-III were higher than those of infested and healthy controls (p<0.01). The total lymphocyte ratios in group III were significantly higher than those of groups I and II (p<0.01). The plasma Zn levels in the supplemented groups were significantly higher than those of control groups IV and V (p<0.01). These results suggest that melatonin and/or Zn supplementation may activate cellular immunity by stimulating CD4+ and CD8+ production in infected rats with T. gondii.


Asunto(s)
Suplementos Dietéticos , Inmunidad Celular/efectos de los fármacos , Melatonina/farmacología , Toxoplasmosis Animal/inmunología , Zinc/farmacología , Animales , Peso Corporal/efectos de los fármacos , Inmunidad Celular/inmunología , Masculino , Ratas , Ratas Sprague-Dawley , Linfocitos T/efectos de los fármacos , Linfocitos T/inmunología , Toxoplasma
18.
Biol Trace Elem Res ; 96(1-3): 255-62, 2003.
Artículo en Inglés | MEDLINE | ID: mdl-14716105

RESUMEN

The present study was designed to investigate the effects of zinc and/or melatonin deficiency on rat testes. A total of 24 adult male Sprague-Dawley rats were used in this study. The rats were divided into four groups of six rats each, as follows: (I) controls, (II) zinc deficient, (III) pinealectomized, zinc normal, and (IV) pinealectomized, zinc deficient. The plasma zinc levels in the control group were higher than in all the other groups (p<0.01), and those of the zinc-deficient groups II and IV were significantly lower than for group III (p<0.01). The melatonin levels in the controls were also significantly higher than for all other groups (p<0.01) There was no significant difference in sperm production between the controls and the group of animals that had no epiphysis. A significant suppression was observed in the spermatogenetic activity of the zinc-deficient groups (p<0.01). The suppression was higher in group II than in group IV. These results indicate that testicular damage caused by zinc deficiency may be reduced by melatonin deficiency.


Asunto(s)
Melatonina/deficiencia , Testículo/metabolismo , Testículo/patología , Zinc/deficiencia , Animales , Masculino , Melatonina/sangre , Glándula Pineal/fisiología , Glándula Pineal/cirugía , Ratas , Ratas Sprague-Dawley , Zinc/sangre
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA
...